Floating action button in action - how to bind to recyclerview in fragment?

Question

I had the same problem in this question Floating action button that doesn't fully display inside the fragment

I have a tablayout in my Activity_main and 2 tabs (with different fragments, one of them contains recyclerView). When I put the FAB in the fragment, the FAB did not show completely until I scroll through the recyclerView.

So, I moved my FAB in the activity_main.xml file to the Coordinator_layout widget, as suggested in the related question, and it works well.

So I have a FAB in action, not in a fragment, and I would like to know how to bind, for example, my fab to a recyclerview in a fragment, for example, so that it comes to life while scrolling through recycler

Now activity_main.xml with tablayout:

activity_main.xml

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" > <android.support.design.widget.AppBarLayout android:id="@+id/appbarlayout1" android:layout_width="match_parent" android:layout_height="wrap_content" android:fitsSystemWindows="true" > <android.support.v7.widget.Toolbar android:id="@+id/toolbar1" android:layout_width="match_parent" android:layout_height="?attr/actionBarSize" app:layout_scrollFlags="scroll|enterAlways" android:background="?attr/colorPrimary" /> <android.support.design.widget.TabLayout android:id="@+id/tabLayout" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/toolbar1" android:background="?attr/colorPrimary" android:scrollbars="horizontal" app:tabMode="scrollable" /> </android.support.design.widget.AppBarLayout> <android.support.v4.view.ViewPager android:id="@+id/viewpager" android:layout_width="match_parent" android:layout_height="match_parent" app:layout_behavior="@string/appbar_scrolling_view_behavior" /> <android.support.design.widget.FloatingActionButton android:id="@+id/fab" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_alignParentRight="true" android:layout_gravity="bottom|right" android:layout_marginBottom="20dp" android:layout_marginRight="20dp" android:src="@drawable/ic_action_location_found" app:fabSize="normal" /> </android.support.design.widget.CoordinatorLayout> 

fragment.xml

 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" android:padding="@dimen/activity_vertical_margin" > <android.support.v7.widget.RecyclerView android:id="@+id/my_recycler_view" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_below="@+id/start_button" android:scrollbars="vertical" /> </RelativeLayout> 

Answer 1

Have you tried to snap it to the viewpager?

 <android.support.design.widget.FloatingActionButton android:id="@+id/fab" app:layout_anchor="@id/viewpager" app:layout_anchorGravity="bottom|right|end" </android.support.design.widget.CoordinatorLayout> 

Then you extend FloatingActionButton.Behavior to respond to CoordinatorLayout events:

 public class ScrollAwareFABBehavior extends FloatingActionButton.Behavior { public ScrollAwareFABBehavior(Context context, AttributeSet attrs) { super(); } @Override public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child, View directTargetChild, View target, int nestedScrollAxes) { return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL || super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, nestedScrollAxes); } @Override public void onNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) { super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed); if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE) { child.hide(); } else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) { child.show(); } } } 

And add this to your FloatingButton:

 app:layout_behavior="com.package.yourapp.ScrollAwareFABBehavior" 

This is well explained here:

https://guides.codepath.com/android/Floating-Action-Buttons

Answer 2

Complementing @petrusgome's answer :

Solution for solution does not work for me. I am having a problem where the FAB will not display again after scrolling through the recyclerview list. To fix this, I just had to replace child.hide() with the following code:

 child.hide(new FloatingActionButton.OnVisibilityChangedListener() { @Override public void onHidden(FloatingActionButton fab) { super.onHidden(fab); fab.setVisibility(View.INVISIBLE); } }); 

Full explanation can be found here: scroll issue